|Li, Xin Liang|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 12, 2007
Publication Date: N/A
Technical Abstract: Trichoderma reesei (Hypocrea jecorina) is one of the most commonly used fungi for the manufacturing of industrial enzyme products. The fungus is capable of secreting proteins in levels up to 100 grams per liter. A number of homologous and heterologous proteins have been successfully over-expressed. For strong inducible expression, the cel7A promoter is usually chosen to drive the expression. The drawback for using the cel7A promoter is that under the induction conditions, the fungus also secretes a number of endogenous cellulases and hemicellulases. The high level of endogenous proteins may reduce the yield of the proteins of interest by saturating the secretory pathway as well as complicate the purification of the protein of interest. To produce the proteins of interest under low endogenous protein background, we have developed a system utilizing the constitutively expressed promoter of the glucose kinase gene of the fungus. The promoter is up-regulated, and low levels of endogenous proteins are secreted when the fungus is grown on glucose as carbon source. The system has been used for the production of several proteins for structure and function analysis. The talk will summarize the results and discuss strategies for high yield production of extracellular proteins by T. reesei at low levels of background proteins.